It is a difference when it comes to limiting the liability. The transactions undertaken outside of the incorporation (in the US at least) means that debt could be attributed to you personally. Your personal assets can be used to pay off the creditors ... whether you want that or not. However, if they are undertaken by the company, then creditors can get the assets that are put into the company, but not your personal assets.

I don’t know which other country you are talking about or which legal structure ... even in the US, the extent of limited liability can vary depending upon which you use. There are partnerships, limited partnerships, S-corps, LLCs, sole proprietorships, etc.